The Triassic in Alaska, US

Paleontology and geology

Though deep marine waters covered the northern third of the state during the Triassic, scattered volcanoes erupted along the ocean floor and continental margin, forming a belt in what is now the central part of the state. Volcanic island arcs formed along the southern and southeastern margins of the state, and reefs built up in shallow areas around these islands. Fossils from this time period include numerous molluscs, icthyosaurs (marine reptiles), and early bony fish.